A power supply system also referred to as electric power grid comprises a plurality of components such as generators, transformers, transmission lines which are vulnerable even to small disturbances or perturbations. These perturbations can cause wide area oscillations which may destabilize the power supply system and which can even lead to cascading outages within the power supply system. Distributed energy resources and renewable energy resources, in particular renewable energy sources, require the power supply networks to adapt to faster changing and sometimes unexpected system conditions. However, a conventional power supply system management relies on offline studies and simulations with data models based on steady-state assumptions. Real-time online data from the power supply network may be used to trigger alarms in case that predetermined system thresholds are reached. An operator of the power supply system has to interpret the received data based on his experience and possibly based on information exchanged with neighbouring grid operators. Root-cause identification of a perturbation within the power supply system requires a time-consuming analysis of multiple time-series data.